The present invention relates to railroad tank cars, and in particular, to an operating mechanism for a valve controlling release of liquid cargo from the bottom of a railroad tank car.
A bottom valve in a railroad tank car is used to drain liquid cargo from the car. Such a valve is located near the lowest point in the cargo tank, usually near the center of the length of the car, between the wheeled trucks that support the car on the rails. Such a valve is usually provided some protection, such as by a substantial structure at least partly surrounding the valve, in order to reduce the danger of release of liquid cargo should the car be derailed. Nevertheless, there has been some danger in the past that a bottom valve operating mechanism might open the bottom valve if a derailed car encounters the ground or other obstructions in such a way that the valve operating mechanism is affected.